Any ethical dilemma is a dilemma because you are choosing between two good things. Any political debate is a debate because values we all care about are being pitting against each other and we're being forced to choose.
Most of life is both/and rather than either/or.
The same goes for the relationship between peace and justice. Wanting peace without justice is wanting a world where no prophet can rock the boat. Peace without justice is reduced to niceness and politeness. On the other side, a justice that is unconcerned with peace and reconciliation will become a purely destructive force.
A similar tension exists between forgiveness and telling the truth.
So we are always managing the tensions. Mercy. Truth. Justice. Peace. And in Psalm 85:10 there's a beautiful image of this:
Mercy and truth have met each other: justice and peace have kissed.The translation here is from the lesser known Douay-Rheims Bible. Most translations translate "justice" as "righteousness." But the point is still clear as "righteousness" involves standing in a right relation before the law, being declared "just" or "justified."
Translations aside, I love the the imagery of managing the tensions in Psalm 85.
We are seeking that place where mercy and truth come together, the moment where justice and peace will kiss.